Tricyclic Antidepressants (TCAs)

Until very recently, tricyclic antidepressants, or TCAs, were the mainstays of treating severe depression.

How TCAs Work

Researchers believe cyclic antidepressants increase the amount of norepinephrine and serotonin between sending and receiving neurons in the brain by slowing their reabsorption, or reuptake, back into the sending neuron.

Unfortunately, these medications also block several other neurotransmitters that may not be associated with depression. As a result, they cause a number of side effects, such as sleepiness, dry mouth, increased appetite, and sexual problems. Taking more than the prescribed amount can cause a potentially fatal overdose. If you or your doctor think you are at risk for suicide, TCAs probably aren't the best choice for you. If you have a plan to commit suicide, or are about to, call 911 or your local emergency number. If you've been thinking about suicide, call your doctor, a local mental health hot line, or mental health services in your community immediately. Or you can call the National Suicide Survival Hot Line 24 hours a day at 1-888-SUICIDE.

Possible Side Effects of TCAs

Listed below are some of the side effects that have been associated with various TCAs. Side effects vary according to which TCA is being used. Also, not everyone who is on these medications will experience these side effects. Side effects vary from person to person. If you have side effects, some may disappear quickly, while others may remain throughout treatment. Elderly patients may be more sensitive to the effects of TCAs. Talk with your doctor if you begin to experience any of these symptoms.

Bothersome Side Effects

  • agitation
  • anxiety
  • blurred vision
  • constipation
  • difficulty urinating
  • dizziness when standing (orthostatic hypotension)
  • dry mouth
  • dry skin
  • fast heart rate
  • fatigue
  • muscle twitches
  • sedation, feeling medicated or sleepy
  • sexual dysfunction
  • sweating
  • weight gain

More Serious Side Effects

  • altered liver function
  • asthma - worsening of symptoms
  • glaucoma - worsening
  • irregular heartbeat (cardiac arrhythmia)
  • loss of consciousness
  • overdose - potentially fatal
  • rashes or other allergic reactions
  • seizures